The invention relates to a level sensor for a fuel tank for generating electrical signals as a function of a pivot angle of a lever arm, which is fitted with a float, for a tank of a motor vehicle, having a support which is provided for attaching it to a side wall in the tank, having a bracket which is made of plastic and can pivot in a bearing of the support, having a lever wire which holds the float and is attached to the bracket, and having a signal transmitter which is actuated by the bracket.
Level sensors of this type are frequently used in fuel tanks of modern motor vehicles and are known in practice. In the known level sensor, an angled section of the lever wire forms a bearing axis for the lever arm. The angled section is routed through holes in the bracket and in the support. The two-part design of the lever arm from a metal lever wire and a bracket usually made of plastic has the advantage that the introduction of vibrations into the bracket and thus into the signal transmitter, in the form of a potentiometer for example, can be kept low. Furthermore, following installation of the level sensor, the lever wire can be bent back in the fuel tank in order to compensate for installation tolerances.
One disadvantage of the known level sensor is that a burr at the end of the angled section of the lever wire may damage the holes in the bracket and in the support, so that the movement of the float deviates from a circular path. In order to prevent damage to the holes, the free end of the angled section has to be deburred, and this is complicated. Furthermore, the angle of the angled section is usually only 89° or less instead of 90°, in order to prestress the bearing. Prestressing the bearing allows a small amount of play. However, this also leads to the movement of the float deviating from a circular path. The level sensor is therefore very difficult to calculate and calibrate.
The invention is based on the problem of developing a level sensor of the type mentioned in the introduction such that it can be produced and calibrated in the most cost-effective way possible.